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9/22/2017 12:11:25 AM
Posted: 9/14/2005 7:43:18 PM EDT
[Last Edit: 9/14/2005 7:43:58 PM EDT by NoNameXII]
Ok. I put together an AR from parts, It is all RRA with the exception of a Bushmaster Barrel. I have only had the opportunity to shoot it twice. The types of ammunition that I had were wolf and some XM855, I think the PD stuff. Anyway, I loaded the magazine with a few rounds of the XM855 and closed the bolt. Fired the first round and the bolt didn't close all the way. I pulled the charging handle back and let it go again. It closed and I fired again. This time it cycled. Well, the problem that I had with cartridges not feeding continued with both kinds of ammuntion. Sometimes it was so bad, that I would have to pull and release the charging handle three or four times to get a cartridge into the chamber. Eventually it smoothed out for the most part as long as I downloaded the magazines (30 rounders, green followers, teflon from ammoman. Way too expensive looking back btw.) to less than 27 rounds. Today, I went to go try to really sight it in (didn't have a rest or enough space before) and I started out with a few magazines loaded with around 10 rds XM855 each. Never had a problem. Ran out of that and started using the wolf, and it wouldn't feed a single round. The bolt wouldn't even close on the first round without trying 3 or 4 times. Granted, this was with fully loaded magazines. I took out quite a few rounds and tried again. Same thing happened. There were some other guys there waiting to use the range, so I just got up and left. Plus it was really embarassing having something that you put together malfunction in front of a bunch of people. What do you guys think is the problem. The lips on the magazines seem kind of sharp; Could I file them down a little to smooth them out? Would it help if I bent the front of the feed lips up just a little to give a better feed angle, or would that interfere with something? Or is it just crappy ammunition? ( I hope not, I just bought 1000 rds of wolf 55gr, and I don't like to throw away money.) Anyway, If someone on here has had a similar experience and possibly a solution, some info sharing would be greatly appreciated.
Link Posted: 9/14/2005 7:47:52 PM EDT
[Last Edit: 9/14/2005 8:05:41 PM EDT by eye_spy]
My eyes!

Welcome to the Board!

Give me a sec. to read thru your post once more and try to think of what may have happened .... off the cuff, i'm thinkin' "short cycling"?

[ETA]

Does it "feed" when you charge the handle initially? Or does it only happen when you shoot it?

If it does not feed on the initial "charge", then the problem may be with your mag. I had that happen to me where when I try to chamber a round, the tip of the bullet hits the bottom of the feed ramp! When I changed my mag, no problems.

I loaded the magazine with a few rounds of the XM855 and closed the bolt. Fired the first round and the bolt didn't close all the way. I pulled the charging handle back and let it go again. It closed and I fired again. This time it cycled. Well, the problem that I had with cartridges not feeding continued with both kinds of ammuntion.

When it FTF (failure to feed) after you fired it, it can be a case of short stroking - where the gas is insufficient to push the bolt back .... or, your buffer spring may also be weak.

Those are just my opinions off the top of my head.

Good luck.
Link Posted: 9/14/2005 7:58:59 PM EDT
[Last Edit: 9/14/2005 8:00:24 PM EDT by NoNameXII]
If I have the bolt open and put a magazine in, I can press the bolt release and it will only go forward about 3/4 to 1 inch, at which point I have to pull and release the charging handle once or twice to get the round to feed in. Although it also fails to feed when cycling after a shot. And the bullets are hitting at the very bottom of the feed ramps from what I could see.

P.S. Sorry about all the text, I just wanted to be as descriptive as possible.

P.P.S. It seems to happen with all three mags that I have to some extent. I will get some new ones to try as soon as I get some more $$$. But until then...
Link Posted: 9/14/2005 8:11:23 PM EDT
Sometimes it was so bad, that I would have to pull and release the charging handle three or four times to get a cartridge into the chamber. Eventually it smoothed out for the most part as long as I downloaded the magazines (30 rounders, green followers, teflon from ammoman. Way too expensive looking back btw.) to less than 27 rounds.

That is either a mag problem or a buffer spring (weak) problem. When you top the mag off with 30 rounds - and press the bullets down in the mag, does it seem too tight / no play left? If that is the case, then its a mag problem. Otherwise, it may be your buffer spring.
Link Posted: 9/14/2005 8:12:00 PM EDT
sounds like it might be a chamber issue and possibly a buffer spring issue....i would have the chamber checked if it were me.....just my thoughts on it thus far....


best of luck.....hope whatever the problem may be that you can get it figured out and running 100% soon so you can start to really enjoy your AR....nothing like assembling one yourself and being able to enjoy the crap out of it.....



camaro
Link Posted: 9/14/2005 8:18:47 PM EDT
[Last Edit: 9/14/2005 8:25:52 PM EDT by StealthyBlagga]
Try a box of regular, quality-brand, brass cased 55grn FMJ ammo (Winchester white box, American Eagle etc.). Not saying for sure its the Wolf, but Wolf is a known cause of problems in some rifles. Otherwise, try a completely new mag of a different brand (Tapco has good GI mags for $11each right now) and replace the buffer spring with another - make sure its the correct type (fixed A2 rifle stock or carbine stock). Lastly, when you charge the rifle, don't use the bolt release but pull the charging handle all the way back then release it - DO NOT ride it forwards at all.
Link Posted: 9/14/2005 9:01:40 PM EDT

Originally Posted By camaro128:
sounds like it might be a chamber issue



By the time the round is even close to the chamber, everything is moving smoothly. I guess I will get some better ammo and try that, then mags, then buffer spring. Do buffer springs really come bad from the factory?
Link Posted: 9/16/2005 7:51:55 PM EDT
I had the same problem with my build, the solution was to replace my buffer spring with a Wolffe Extra Power buffer spring. You need to check your bolt for free movement with-out lower attached, check to make sure your bolt or firing pin isn't catching on the hammer, make sure your bolt isn't binding in buffer tube or any other mechanical cause before going to an Xtra Power buffer spring. I'm sure my new spring was on the weak side so an XP spring was the way to go, don't try to fix a binding or mechinal problem by increasing the spring strength. If your buffer spring is weak you could just get a regular strength spring and after a little break in every thing should be o k. AR's take a bit of break in to function 100% so don't be to disapointed yet. If you decide on the XP spring you will short stroke with weak ammo like wolf and possibly non NATO ammo as well.
Link Posted: 9/20/2005 5:49:04 PM EDT
Update. I am probably going to catch all sorts of hell for this, but after trying various things which worked to some extent, I decided to take a small rat-tail file and cut what basically amount to M4 feed ramp cuts in my upper. I didn't think that my barrel (Bushmaster 16" patrolman's carbine.)had these feed ramps in it, but looking closer, I could see a little bit of the upper at the bottom of the feed ramps, and there were marks just below the feed ramps from the tips of the bullets feeding against that area. This solved all of my problems save one, on all except two of the magazines that I fired, just hitting the bolt release would not chamber the round completely, I still had to pull the charging handle all the way back. Does this mean that my buffer spring is defective? As a side note, I fed one round directly into the chamber with none in the magazine, but the magazine in the rifle, and after firing it, I found the case lodged between the front of the ejection port and the bolt, like the bolt never went far enough back to get on the bolt catch. This is the only time I had any problems with cycling.
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